ECG089
Energy Consumption Guide
Energy Use in Pig Farming
Contents
1 Introduction
01
2 Background to this Guide
01
3 Measuring energy efficiency
4 Establishing the facts
and planning actions
01
01
01
4.3 Identifying energy
efficiency measures
5 Energy saving measures
5.1 Energy management approach
5.2 High priority / low cost measures
5.2.1 Monitor energy use
5.2.2 Carry out maintenance and repairs
5.2.3 Check the accuracy of controls
5.2.4 Use information from your
control system
5.3 Medium and long term actions
5.3.1 Improve building insulation
5.3.2 Use enclosed creeps
5.3.3 Improve controls
06
6.2 Weaning accommodation
07
6.2.2 Kennels
6.3 Finishing accommodation
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08
10
Further reading
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ECA Scheme
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Carbon Trust Energy Surveys
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Acknowledgements
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04
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5.3.4 Use efficient fans and ducts
04
5.3.6 Use high efficiency motors and
variable speed drives on feed and
waste handling systems
05
5.3.5 Efficient lighting
06
6.1 Farrowing heating
6.2.1 Weaner rooms
4.1 Taking stock of the
current situation
4.2 Comparing performance
6 Appendix
Main energy uses
– detailed breakdown
05
Energy Use in Pig Farming
1 Introduction
Pig farmers use energy in both intensive and
extensive rearing systems in order to achieve
their production goals. The main uses of energy
are for building services, animal feeding systems
and waste removal. Energy also plays an important
part in animal welfare and environmental
protection, most notably in waste management
and emissions control.
Energy use can be minimised and costs reduced
through sensible selection of system components,
wise use of insulation and attention to design and
operation of control systems. Any alterations should
take full account of the pigs’ environmental
requirements and welfare. It is often the case that
improvements in control systems and insulation will
enhance the pigs’ environment.
2 Background
to this Guide
This guide presents benchmark data on ‘typical’ and
‘good practice’ levels of energy consumption for pig
farms in the UK.
Benchmarks are valuable because they allow
producers to compare their performance with
other similar businesses. In addition, they also
provide two other useful functions:
1. They allow routine assessments to be made
that show progress against a benchmark. Such
appraisals are not restricted to year-on-year
evaluations as they can be carried out quarterly,
monthly or even weekly to track progress.
2. Opportunity assessments can be carried out.
For example, if a facility is to be modified
or upgraded, the effect of the change can
be determined.
Throughout this guide, the benchmarks and
information are based on methods and techniques
that minimise energy consumption whilst maintaining
pig performance at an economically acceptable level.
Pig farming in the UK is a complex and diverse
business with a variety of facilities being used
for each stage of production. To produce guidelines
for all production system combinations would be
an extremely time consuming and difficult task.
Therefore, in order to give realistic guidelines,
production has been broken down into several
key areas to illustrate typical performance with
benchmarks. These production areas are:
• Farrowing accommodation
• Weaning accommodation
• Finisher accommodation
• Feeding system
• Waste handling.
3 Measuring energy
efficiency
Energy use benchmarks relate energy use to numbers
of pigs produced or kilogram (kg) of pig meat. In this
way, businesses of dissimilar size or output can easily
be compared.
Energy benchmarks are therefore a measure of energy
use intensity, the most common units being kWh/pig
and energy use per liveweight produced (kWh/kg).
The data used in this guide was obtained under the
auspices of a Carbon Trust funded project from many
sources including FEC Services Ltd and the National
Pig Association (NPA). The data was collected and
analysed to provide energy savings information,
measures and benchmarks.
4 Establishing the facts
and planning actions
4.1 Taking stock of the
current situation
Before a business can make use of energy
benchmarks, it must carry out a simple assessment
to establish energy use. This involves collecting
information on the amount of energy used and
calculating the energy intensity (total energy
use for the previous year divided by total
animal production).
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4.2 Comparing performance
Once the energy intensity has been calculated,
performance can be compared with the appropriate
benchmark. Having done this comparison, you may
wish to take one of the following courses of action:
• If the figure is more than typical, urgent action
is required to reduce energy consumption. Some
measures are suggested in Section 5
Production
stage
Farrowing
Energy range per pig produced
Typical
8kWh
Good practice
4kWh
Weaning
9kWh
3kWh
Finishing
10kWh
6kWh
Feeding
system
3kWh
1kWh
Waste
management
6kWh
2kWh
(fan ventilated)
(slurry systems)
• If the figure is between typical and good practice
then action is still needed to improve performance
• If performance is in line with good practice, there
is still scope for improvement although the need to
make changes is less urgent.
Use the figures in Table 1 to benchmark your energy use.
Main influence
Use of box creeps with thermostatic control
gives the lowest running cost. Under-floor heating
pads are generally more energy efficient than
infra-red bulbs
Major issues are the insulation of buildings
(or kennels) and most importantly, the control
of ventilation
Efficient fan selection, good design of inlets and
outlets and system cleaning are the key points to
minimising energy use
Dry feeding systems use a small amount of energy
for conveying. Wet feeding is generally more energy
intensive because of the need to mix pump feed and
pressurise pipework
Selection of high efficiency pumps, aerators
and separators
Table 1 Benchmark figures for energy use
4.3 Identifying energy
efficiency measures
Section 5 contains information on measures that can
help make energy efficiency improvements. These
methods can be used on an existing farm or at the
design stage for new or refurbished facilities.
The savings figures quoted can be applied to the
calculated energy intensity to determine the likely
effectiveness of using the techniques described.
Heated floor pads are particularly economical
for open creeps
Energy Use in Pig Farming
5 Energy saving
measures
5.1 Energy management approach
Establishing an energy action plan is the essential
foundation for the reduction of energy waste in
any business. The plan should consider all of the
information available to the company and should
have the backing of senior management.
GPG323: ‘Energy saving guide for agriculture and
horticulture’ gives detailed information on how
to set up an energy action plan.
Visit www.thecarbontrust.co.uk/energy or call the
help line on 0800 58 57 94 for further information.
5.2 High priority / low cost measures
In general, it is best to initially implement low cost
and no-cost measures which require little or no
capital expenditure. In many cases, these measures
give the best rewards as significant savings can often
be made quickly and for little effort and expenditure.
Examples of low cost actions are as follows:
5.2.1 Monitor energy use
This is the basis of good energy management.
Without detailed energy use data, it is impossible
to get a complete and accurate picture of how
energy is used in the business.
Do not rely on utility bills alone as these can often
be based on irregular or estimated meter readings.
Take regular meter readings and record these in
a systematic manner. Make this part of your usual
routine to ensure you obtain frequent and accurate
information.
If you are billed on a monthly basis then take
readings at least weekly; likewise if you are billed
quarterly, then take readings at least every month.
Relate the information collected to production levels
and external influences like the weather. Tracking
progress in this way will give an early warning of any
unexpected changes in consumption which could be
indicative of faulty equipment, altered controls or
other problem. Correcting the problem will lead to
energy savings.
5.2.2 Carry out maintenance and repairs
Simple repairs are often overlooked but they
are an essential part of reducing wasted energy.
Dust and corrosion are major problems for heaters,
ventilation components and controllers. Equipment
should be selected carefully to ensure that it is
capable of enduring an aggressive environment.
Cleaning of all components should be carried out
as part of the ‘end of batch’ cleaning programme.
This should include inspection of duct interiors,
inlet baffles, fans and heater reflectors.
5.2.3 Check the accuracy of controls
Temperature sensors on building environmental
systems should be regularly checked for accuracy.
Use a reference thermometer to check readings and
when inaccuracies are found, take immediate action.
5.2.4 Use information from your
control system
Many modern controllers have the facility to store
temperatures and ventilation settings. These can be
downloaded at a later date to show how ventilation
and heating systems have performed. Linking this
information to energy use can reveal areas of
wastage caused by incorrect setting of controls.
5.3 Medium and long term actions
5.3.1 Improve building insulation
Good insulation is important in all pig housing
systems. Where heating is being used, insulation
cuts heat loss and costs. In unheated finishing
accommodation, insulation also prevents
excessive temperature rises from solar gain.
Current recommendations are for an insulation level
of better than 0.4W/m 2/˚C (60mm polyurethane).
Insulation in older buildings and structures is often
based on fibre-wool type materials. Compression
and slipping of this material can mean that
insulation levels and coverage decrease over time.
Best results can be achieved using composite
panels containing solid polyurethane insulation.
These panels can be bought with plastic coated
steel cladding for durability and cleanliness.
They can also be used as effective structural
components — especially useful in kennel construction.
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5.3.2 Use enclosed creeps
Open creep areas have substantial heat losses so
it is advisable to use boxed creeps. Boxing a creep
provides a controllable environment for the piglets
and allows better regulation of the thermal
environment.
Enclosed creeps vary in construction from fully
sealed and insulated boxes with pop-holes protected
by strip plastic curtains, to crude, open sided areas
with un-insulated lids. The better the construction,
the more heating energy can be contained and
therefore, the more effective controls will be
in maintaining the correct temperature at lowest
energy input. An ideal construction will be well
sealed and insulated.
5.3.3 Improve controls
Good controls are a prerequisite for maintaining
the right temperature in buildings and minimising
the use of energy. For creep heating, use either fully
variable manual dimmers or thermostatic controls.
note of the rated air throughput of the fan at the
operational pressure it requires, together with
the energy rating. Fan efficiency is stated in airflow
per unit energy (e.g. m3/h per W).
When buying fans, consider the ‘lifetime’ cost.
This means taking into account the energy cost
of the fan over its operation life as well as its
initial capital cost.
Because of the sustained operation of fans in
a typical finishing building for instance, a single
fan will consume its own value in energy in about
18 months. So spending, say, 10% more in capital
terms to secure a 10% energy saving will pay
back in around the same time — a very good
return on investment.
Most manufacturers produce performance
characteristics measured to ISO5801 part 1,
which can be used in selection of the most
efficient unit.
The following characteristics should be noted
when considering the efficiency of fans:
• Fan efficiency generally increases with
impeller diameter
• Belt driven fans are generally more efficient
than fans with direct drives
• Fans fitted with proprietary ‘bell-mouths’
to smooth the passage of the air will be
10% more efficient than fans fitted into
a basic circular diaphragm
• Fitting ‘cones’ to outlet fans will increase
efficiency by 10-15%.
Ventilation inlet and outlet ducting should be sized
adequately. The internal surfaces should be smooth
and clean with slow bends.
Covered creeps with thermostatic
control give lowest running costs
Where heating is used in the building (e.g. for
weaning accommodation), it is critical that the
minimum winter ventilation rate is controlled
accurately. If the level is too high then heating
costs will increase dramatically. Too low a level
will produce foul air conditions.
5.3.4 Use efficient fans and ducts
It is important to recognise that fans vary
significantly in their efficiency. Take particular
Clean fans and use smooth inlet bell mouths
to improve efficiency
Energy Use in Pig Farming
5.3.5 Efficient lighting
Prolonged periods of use mean that fluorescent
lighting will afford the most efficient solutions
in most cases. As two different levels of lighting
are generally required (depending on whether the
stockman is present in the room or not), lighting
can be split into two circuits:
• For high level lighting, strip fluorescent lamps
with T8 tubes and electronic control gear will
give the best energy efficiency and most even
light distribution
• For low level lighting in smaller rooms, a small
number of compact fluorescent lamps is a good
solution. An alternative would be to use strip
fluorescent lamps with dimmable ballasts to
allow the lights to be turned down during stock
lighting periods.
Lighting control is generally confined to manual
switching. Typical lighting costs are detailed in
Table 2.
Lighting type
Efficiency characteristics
Tungsten bulbs
Cheap but very inefficient
Can be dimmed for dual stockman/stock use
Compact
fluorescent bulbs
Fluorescent
strip lighting
Often used as a direct replacement for tungsten lights
but cannot be dimmed
Choose T8 (11/4 inch) tubes rather than T12 (11/2 inch)
tubes as these are more efficient
Energy use
(kWh/pig)
2 to 4
0.4 to 0.8
0.4 to 0.8
Fittings with electronic control gear should be
considered as they give a 20% energy saving over
conventional wire wound ballasts and extend lamp
life by 50%
Electronic types are available with dimmable facilities
allowing dual use for stockman/stock
Table 2 Typical energy use for lighting
5.3.6 Use high efficiency motors and
variable speed drives on feed
and waste handling systems
High efficiency motors cost no more than standard
motors and should be considered when specifying or
upgrading motors on feed or waste handling systems.
With wet feeding and slurry pumping systems,
select pumps that give the best flow/energy
characteristics. Pumps which are used to service a
variable demand should be linked to Variable Speed
Drives (VSDs). These drives enable the output speed
of the pumps to match the volumes and pressures
required at different times of the operational cycle.
Savings of between 30-50% can be expected in pump
running costs when using VSDs.
With aeration, it is important to choose a technique
with a high specific oxygen transfer rate per unit of
energy input (kg O2/kWh). This should be checked
with the manufacturer of the system.
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6 Appendix
Main energy uses — detailed breakdown
6.1 Farrowing heating
About a third of the energy used on pig breeding
units is for farrowing (creep) heating.
Creep heating systems come in a number of
forms and designs. The basic types are:
• Radiant electrical — either using a brightemitter lamp (pig lamp) or a dull emitter
(black-bar/black-panel)
• Gas radiant — using small, direct acting radiant
heaters normally running on liquid petroleum
gas (LPG)
• Underfloor heating — either by direct cables laid
in the floor or by hot water pipes fed from a boiler.
Energy use is influenced by the control system, the
type of heating chosen and whether creeps are
boxed or open.
Benchmark energy use for creep heating is as follows:
Open creep
electric / gas radiant
Typical
Average annual
usage (kWh/pig)
8.4
Good
practice
5.0
Measure
Careful control of heater output
Clean heaters and ensure they fit
well into creep lids
Seal boxed creeps and fit pophole curtains
Install boxed creeps
Install thermostatic controls ideally
with temperature profiling
Choose higher efficiency heating type
Table 3 Energy saving measures for creep heating
Boxed creep
electric radiant
Typical
Good
practice
6.0
4.0
Low/medium/high
cost
No cost
Underfloor
Typical
5.0
Good
practice
Payback
period
Immediate
Low
2–3 months
Medium
1–2 years
High
2–3 years
High
3–5 years
High
3–5 years
3.0
Energy Use in Pig Farming
6.2 Weaning accommodation
Most weaner housing incorporates heating and
ventilation and it is the heating that accounts for most
of the energy use. The housing system for this stage of
production can be categorised into two main types:
1. Weaner rooms (flat-decks) — where pigs are fully
housed in a walk-in controlled environment room
on an all-in, all-out basis
2. Kennels — where groups of pigs are housed in
small batches in low level kennels, usually with
solid floors and straw bedding.
Well constructed kennels can give good
energy performance
6.2.1 Weaner rooms
Weaner Room Energy Consumptions
16
14
kWh/pig
12
10
8
6
4
Ventilation
2
Lighting
Heating
0
25 Jul
25 Aug
03 Oct
06 Nov
05 Dec
07 Jan
18 Feb
04 Apr
21 May
27 Jun
date
Typical energy profiles for batches of pigs in a weaner room
Kennel Energy Consumptions
The energy profile shown above was for a 26 m2,
9 room with pigs housed from 3 -7 weeks of
120 pig
age. Heating was from 4 x 1.5kW electric heaters
8
and ventilation
from 2 x 355mm fans.
10
kWh/pig
7
6
5
4
3
2
This information should be regarded as an example
of the ‘typical’ usage profile. Evidence shows quite
a wide range of energy use from 6-17 kWh/pig,
mainly due to variations in heating demand.
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Typical
Average annual
usage (kWh/pig)
Heating
Good
practice
Typical
3.0
7.5
Lighting
Ventilation
Good
practice
2.0
Typical
1.0
Good
practice
0.8
0.6
Typical and good practice benchmarks for a weaner room
Weaner Room Energy Consumptions
6.2.2 Kennels
16
The energy profile shown below was for a 4 m2,
12
20 place
kennel with pigs from 3-5 weeks of age.
Heating was provided by 1kW underfloor heating
10
elements. The kennels were fitted with automatically
controlled
natural ventilation (ACNV).
8
kWh/pig
14
Kennel Heating
6
Typical
4
2
Average
annual
0
usage (kWh/pig)
25 Jul 25 Aug
6.5
03 Oct
Good
practice
Ventilation
Lighting
3.0
06 Nov
05 Dec
Heating
07 Jan
date
Typical and good practice benchmarks for a kennel
18 Feb
04 Apr
21 May
27 Jun
ACNV uses little energy
Kennel Energy Consumptions
10
9
8
kWh/pig
7
6
5
4
3
2
1
Heating
0
25 Apr
29 May
04 Jul
30 Jul
28 Aug
01 Oct
date
Typical energy profiles for batches of pigs in a kennel
29 Oct
17 Dec
21 Jan
18 Feb
25 Mar
Energy Use in Pig Farming
Measure
Closer setting of controls
Low/medium/high cost
Payback period
Low
Under 1 year
Low–High
1–5 years
Seal buildings to stop draughts
Clean fans and ducting regularly
Install compact fluorescent lighting or high
efficiency tubular fluorescent lighting
Reconfigure ventilation to give
better control of minimum level
Update heating and ventilation controls
Re-insulate buildings
Table 4 Suggestions for energy saving measures
No cost
Low
Immediate
Under 1 year
Medium
1–3 years
Medium
1–3 years
High
3–5 years
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6.3 Finishing accommodation
Since the metabolic heat output of growing pigs
increases with weight and their temperature
requirement falls, ventilation systems in finishing
buildings are of a higher capacity than those
required in farrowing or weaning. Ventilation is
therefore the major energy user at this stage of
production and the careful choice of fans, the
design of ducts and the maintenance of these
systems is critical for efficient operation.
Lighting and feeding systems are the next most
important users of energy.
Drastic reduction in energy use can be achieved
by using natural ventilation or ACNV, but building
temperature control may suffer leading to feed
conversion increases. Also note that not all building
designs lend themselves to conversion to these
systems.
Finishing building
ventilation using fans
Typical
Average annual
usage (kWh/pig)
7.2
Good
practice
4.0
Typical and good practice benchmarks for
finishing accommodation
Measure
Make sure controls are properly
calibrated and set to the
correct temperature
Clean fans and ducting regularly
Low/medium/high cost
Payback period
Low
Under 1 year
No cost
Immediate
Install compact fluorescent
lighting or high efficiency
tubular fluorescent lighting
Low–High
Medium
3–5 years
Update ventilation controls
Medium
3–5 years
Improve the design of inlets and outlets
to provide smoother air passage and
lower air speeds
Update ventilation to high efficiency
low loss system
Re-insulate buildings to reduce solar gain
1–5 years
High
4–6 years
High
4–6 years
Table 5 Suggestions for energy saving measures for finishing accommodation
Energy Use in Pig Farming
Further reading
GPG323: ‘Energy saving guide for agriculture
and horticulture’
GPG376: ‘A strategic approach to energy
and environmental management’
ECA Scheme
The Enhanced Capital Allowance (ECA) scheme aims
to encourage business to reduce carbon emissions
through providing an incentive to invest in energyefficient technologies.
Carbon Trust
Energy Surveys
Free professional and impartial advice to help
you cut your energy bills.
An Energy Survey is a free, government-funded
service that offers organisations the opportunity
to identify and implement energy saving measures.
For further information on ECA’s or surveys, contact
the helpline on 0800 58 57 94 or visit the web site
at www.thecarbontrust.co.uk/energy
Acknowledgements
The Carbon Trust gratefully acknowledges the support
in production of this energy consumption guide from
FEC Services Ltd and the National Pig Association
(NPA). All images are copyright of FEC Services Ltd.
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Notes
Tel 0800 58 57 94
www.thecarbontrust.co.uk/energy
The Carbon Trust is funded by the Department for Environment,
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for Wales and Invest Northern Ireland.
Whilst we have taken reasonable steps to ensure that the information
contained within this leaflet is correct, we give no warranty and make
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